The present invention relates to disperse dyes having an N-alkyl-phthalimide-diazo component and an aniline coupling component, to processes for the preparation of such dyes and to the use thereof in dyeing or printing fibre materials, especially polyester-containing fibre materials.
Disperse azo dyes having an N-alkyl-phthalimide-diazo component and an aniline coupling component have been known for a long time and are used in dyeing hydrophobic fibre materials. It has, however, been found that the dyeings or prints obtained using the currently known dyes do not in all cases satisfy today""s requirements, especially in respect of fastness to washing and fastness to perspiration. There is therefore a need for new dyes that especially have good washing fastness properties.
It has now been found, surprisingly, that the dyes according to the invention meet the criteria given above to a considerable degree.
The present invention accordingly relates to disperse dyes that yield dyeings having a high degree of fastness to washing and to perspiration and that, in addition, have good build-up characteristics both in the exhaust and thermosol process and in textile printing. The dyes are also suitable for discharge printing.
The dyes according to the invention correspond to formula 
wherein
R is methyl or butyl,
R1 is hydrogen, halogen, cyano or nitro,
R2 is halogen or cyano,
R3 is hydrogen, halogen, C1-C4alkyl or C1-C4alkoxy,
R4 is hydrogen, C1-C4alkyl, halogen, CF3 or xe2x80x94NHCOR7 wherein R7 is C1-C4alkyl,
R5 is C1-C6alkyl that is unsubstituted or substituted by hydroxy, cyano, acyloxy, 
xe2x80x83or by phenoxy, x being a number from 0 to 4 and it being possible for the alkyl chain, from C2 upwards, optionally to be interrupted by one or more oxygen atoms, or is a radical of formula xe2x80x94CH2CH2xe2x80x94Oxe2x80x94COR8 or of formula 
and R6 is a radical of formula xe2x80x94CH2CH2xe2x80x94Oxe2x80x94COR8, of formula 
xe2x80x83or of formula 
xe2x80x83R8 and R9 each independently of the other being C1-C4alkyl and R10 being hydrogen or C1-C4alkyl, or, when R is methyl, R5 and R6 are each independently of the other C1-C4alkyl,
xe2x80x83with the proviso that when R is n-butyl and R5 and/or R6 is/are a radical of formula xe2x80x94CH2CH2xe2x80x94Oxe2x80x94COR8, R4 may not be chlorine or acetylamino.
R as butyl is n-butyl, iso-butyl, sec-butyl or tert-butyl.
Importance is given to R as methyl or n-butyl, especially methyl.
R1 and R2 as halogen are, each independently of the other, for example, fluorine, chlorine or bromine, especially chlorine or bromine, more especially bromine.
R3 and R4 as halogen are, each independently of the other, for example, fluorine, chlorine or bromine, especially chlorine or bromine, more especially chlorine.
R3, R4, R5, R6, R7, R8, R9and R10 as C1-C4alkyl are, each independently of the others, methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl or tert-butyl, with the following preferences:
As R3, preference is given to ethyl or, especially, methyl.
As R4, preference is given to ethyl or, especially, methyl.
As R5, preference is given to methyl or, especially, ethyl.
As R6; preference is given to propyl and, especially, ethyl.
As R7, preference is given to ethyl or, especially, methyl.
As R8, preference is given to ethyl or, especially, methyl.
As R9, preference is given to methyl and, especially, ethyl.
As R10, preference is given to methyl.
R3 as C1-C4alkoxy is, for example, methoxy, ethoxy, straight-chain or branched propoxy or straight-chain or branched butoxy. Preference is given to ethoxy or, especially, methoxy. A suitable acyloxy substituent in R5 is, especially, propionyloxy or, more especially, acetoxy.
In the meaning of x preference is given to 2 or, especially, 1.
R5 as substituted C1-C6alkyl is especially cyano-substituted C1-C4alkyl, more especially cyanoethyl.
As R1, special preference is given to hydrogen, bromine or cyano, especially hydrogen or bromine.
As R2, special preference is given to bromine or cyano, especially bromine.
As R3, special preference is given to hydrogen.
As R4, special preference is given to hydrogen or xe2x80x94NHCOR7, the definition and preferred meanings given above applying to R7.
As R4, very special preference is given to xe2x80x94NHCOR7, the definition and preferred meanings given above applying to R7.
As R5, special preference is given to ethyl or cyanoethyl.
As R6, special preference is given to ethyl or, especially, to the radical xe2x80x94CH2CH2OCOCH3.
As R6, special preference is likewise given to the radical 
the definitions and preferred meanings given above applying to R9 and R10.
As R6, very special preference is given to the radical xe2x80x94CH(CH3)xe2x80x94COOC2H5.
Special preference is given to dyes of formulae
Special preference is likewise given to dyes of formulae
Special preference is likewise given to dyes of formulae
Very special preference is given to dyes of formulae 
The present invention relates also to the process for the preparation of the dyes of formula (1) according to the invention.
The dyes are prepared, for example, by nitration of a phthalimide of formula 
in the acid range, as described, for example, on page 459 in Organic Synthesis, Collective Volume 2, (a Revised Edition of Annual Volumes X-XIX), J. Wiley and Sons, followed by alkylation of the resulting nitro compound, for example in accordance with a method described in Journal of Organic Chemistry 32 (1967) on page 1923, paragraph 3, and, for example after reductive treatment described in Bull. Soc. Chim. de France 1957 on page 569, conversion into an intermediate of formula 
wherein R has the definition and preferred meanings given above.
Using generally known methods, the intermediate of formula (51) is, in an acid medium, nitrated or mono- or poly-halogenatedxe2x80x94it being possible, if desired, for the halogen substituents to be replaced by cyano using methods that are also generally knownxe2x80x94and then diazotised and coupled to a compound of formula 
wherein R3, R4, R5 and R6 have the definitions and preferred meanings given above.
The halogenation is carried out, for example, by reacting the compound of formula (51) first with sodium acetate in acetic acid and then with bromine in the same medium to form the corresponding mono- or di-bromo compound.
The diazotisation of the compound of formula (51) is likewise carried out in a manner known per se, for example with sodium nitrite in an acidic, for example hydrochloric acid-containing or sulfuric acid-containing, aqueous medium. The diazotisation may, however, also be carried out using other diazotisation agents, e.g. with nitrosylsulfuric acid. In the diazotisation, an additional acid may be present in the reaction medium, e.g. phosphoric acid, sulfuric acid, acetic acid, propionic acid, hydrochloric acid or mixtures of such acids, e.g. mixtures of propionic acid and acetic acid. The diazotisation is advantageously carried out at temperatures of from xe2x88x9210 to 30xc2x0 C., for example from xe2x88x9210xc2x0 C. to room temperature.
The coupling of the diazotised compound of formula (51) to the coupling component of formula (52) is likewise effected in known manner, for example in an acidic, aqueous or aqueous-organic medium, advantageously at temperatures of from xe2x88x9210 to 30xc2x0 C., especially below 10xc2x0 C. Examples of acids used are hydrochloric acid, acetic acid, propionic acid, sulfuric acid and phosphoric acid.
The diazo components of formula (51) and the coupling components of formula (52) are known or can be prepared in a manner known per se.
The dyes according to the invention may be used as dyes for dyeing and printing semi-synthetic and especially synthetic hydrophobic fibre materials, especially textile materials. Textile materials composed of blend fabrics that comprise such semi-synthetic or synthetic hydrophobic fibre materials can also be dyed or printed using the compounds according to the invention.
Semi-synthetic fibre materials that come into consideration are, especially, cellulose 2xc2xd-acetate and cellulose triacetate.
Synthetic hydrophobic fibre materials consist especially of linear, aromatic polyesters, for example those of terephthalic acid and glycols, especially ethylene glycol, or condensation products of terephthalic acid and 1,4-bis(hydroxymethyl)cyclohexane; of polycarbonates, e.g. those of xcex1,xcex1-dimethyl-4,4-dihydroxy-diphenylmethane and phosgene, and of fibres based on polyvinyl chloride and on polyamide.
The application of the compounds according to the invention to the fibre materials is effected in accordance with known dyeing methods. For example, polyester fibre materials are dyed in the exhaust process from an aqueous dispersion in the presence of customary anionic or non-ionic dispersants and, optionally, customary swelling agents (carriers) at temperatures of from 80 to 140xc2x0 C. Cellulose 2xc2xd-acetate is dyed preferably at from 65 to 85xc2x0 C. and cellulose triacetate at temperatures of from 65 to 115xc2x0 C.
The dyes according to the invention will not stain wool and cotton present at the same time in the dyebath or will stain such materials only slightly (very good reservation) so that they can also be used satisfactorily in the dyeing of polyester/wool and polyester/cellulose fibre blend fabrics.
The dyes according to the invention are suitable for dyeing in accordance with the thermosol process, in the exhaust process and for printing processes.
In such processes, the said fibre materials can be in a variety of processing forms, e.g. in the form of fibres, yarns or nonwoven, woven or knitted fabrics.
It is advantageous to convert the dyes according to the invention into a dye preparation prior to use. For this purpose, the dye is ground so that its particle size is on average from 0.1 to 10 microns. Grinding can be carried out in the presence of dispersants. For example, the dried dye is ground together with a dispersant or kneaded into a paste form together with a dispersant and then dried in vacuo or by atomisation. After adding water, the resulting preparations can be used to prepare dye pastes and dyebaths.
For printing, the customary thickeners will be used, e.g. modified or unmodified natural products, for example alginates, British gum, gum arabic, crystal gum, locust bean flour, tragacanth, carboxymethyl cellulose, hydroxyethyl cellulose, starch or synthetic products, for example polyacrylamides, polyacrylic acid or copolymers thereof, or polyvinyl alcohols.
The dyes according to the invention impart to the said materials, especially to polyester materials, level colour shades having very good in-use fastness properties such as, especially, good fastness to light, fastness to heat setting, fastness to pleating, fastness to chlorine, and wet fastness, e.g. fastness to water, to perspiration and to washing; the dyeings are further characterised by very good fastness to rubbing. Special emphasis should be given to the good fastness properties of the dyeings obtained with respect to perspiration and, especially, to washing.
The dyes according to the invention can also be used satisfactorily in producing mixed shades together with other dyes.
Furthermore, the dyes according to the invention are also well suited to dyeing hydrophobic fibre materials from supercritical CO2.
The present invention relates to the above-mentioned use of the dyes according to the invention as well as to a process for the dyeing or printing of semi-synthetic or synthetic hydrophobic fibre materials, especially textile materials, in which process a dye according to the invention is applied to the said materials or incorporated into them. The said hydrophobic fibre materials are preferably textile polyester materials. Further substrates that can be treated by the process according to the invention and preferred process conditions can be found above in the more detailed description of the use of the dyes according to the invention.
The invention relates also to the hydrophobic fibre materials, preferably polyester textile materials, dyed or printed by the said process. The dyes according to the invention are, in addition, suitable for modern reproduction processes, e.g. thermotransfer printing.